Identifying Harmful Algae Blooms

Large populations of blue-green algae may produce toxins at a high enough level to affect those using the water for drinking or recreational use. Individual cyanobacteria cells and green algae cannot be seen with the unaided eye. However, they may cluster together to form visible algae blooms. The photos below illustrate what possible Blue-green harmful algae blooms may look like. A laboratory analysis of a water sample must be completed to determine if toxins are present.